Blend Shapes

Path of the scene: [03_blend_shape]
This code load a set of meshes corresponding to different key poses for the same character face.
In the current implement all the poses are stored as an array of meshes (see src/blend_shape directory). The first entry of the array will be considered to be the reference pose (faces_storage[0]).
The GUI propose a set of sliders to control the weights associated to each pose but is without effect in the current state.
> Implement a blend shape deformation controled interactively by the blend shape weights using the formulation: \[\displaystyle q_i=p_i + \sum_{j}^{N_{poses}} w_j \, d_{ij}\]